Step 1: Divide the number into separate digits:
02732 => 0 2 7 3 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 2 = 2
2 to 7 = 5
7 to 3 = 4
3 to 2 = 1
2 to 0 = 2
Step 3: Combine the filters to a string:
2 5 4 1 2 = 25412